Related Experiment Video
Updated: Jul 3, 2026
11:47
Evaluation of the Efficacy of Organic Peroxyacids for Eradicating Dairy Biofilms Using an Approach Combining Static and Dynamic Methods
Published on: December 9, 2022
Biodegradation of chlorophenol mixtures by Pseudomonas putida
1Department of Chemical Engineering, University of Saskatchewan, Saskatoon, Saskatchewan, S7N 0W0, Canada.
Biotechnology and Bioengineering
|December 20, 1992
Summary
Pseudomonas putida growth is inhibited by phenol and chlorophenols. Logarithmic growth only occurs when monochlorophenols are co-metabolized with phenol, with increasing concentrations extending lag times.
Area of Science:
- Microbiology
- Environmental Science
- Biotechnology
Background:
- Phenolic compounds, including phenol and monochlorophenols, are common environmental pollutants.
- Pseudomonas putida is a bacterium known for its metabolic versatility and potential in bioremediation.
- Understanding microbial growth dynamics is crucial for developing effective bioremediation strategies.
Purpose of the Study:
- To investigate the growth behavior of Pseudomonas putida in the presence of inhibitory concentrations of phenol and monochlorophenol mixtures.
- To model the lag and logarithmic growth phases of P. putida under varying substrate conditions.
- To determine the impact of phenol and monochlorophenol concentrations on growth kinetics and yield.
Main Methods:
- Inoculating resting cells of Pseudomonas putida into growth media with inhibitory concentrations of phenol and monochlorophenols.
- Monitoring biomass growth and calculating apparent death rates.
- Developing empirical correlations to model lag-phase duration, specific growth rate, and log growth yield coefficient.
Main Results:
- Apparent death rates decreased with increasing concentrations of phenol or chlorophenols.
- Logarithmic biomass growth was not observed on pure monochlorophenols but occurred during co-metabolism with phenol.
- Lag phase duration increased exponentially with phenol concentration and linearly with monochlorophenol concentration.
- Log growth yield coefficient decreased linearly with monochlorophenol concentration.
- Specific growth rate decreased exponentially with monochlorophenol concentration, with significant inhibition observed even at low ppm levels.
Conclusions:
- Co-metabolism of monochlorophenols with phenol is essential for P. putida logarithmic growth.
- Phenol and monochlorophenols exhibit complex inhibitory effects on P. putida growth kinetics.
- Empirical models developed can accurately predict the growth behavior of P. putida on these mixed phenolic substrates.
Related Concept Videos
01:28Microbial Bioremediation of Pesticides
Pesticides often feature structurally complex chemical architectures, incorporating halogen groups and multiple aromatic rings. These characteristics confer high chemical stability, rendering many pesticides resistant to natural degradation processes. This resistance poses significant environmental concerns, as persistent pesticide residues can accumulate in ecosystems and affect non-target organisms.Despite the inherent stability of many pesticides, certain microorganisms possess the metabolic...
01:27Bioplastics
Bioplastics derived from microbial processes present a sustainable alternative to conventional petroleum-based plastics. Among these, polyhydroxyalkanoates (PHAs), particularly polyhydroxybutyrates (PHBs), have emerged as prominent candidates due to their biodegradability and biocompatibility. These polymers are synthesized by a variety of bacteria, such as Cupriavidus necator and Pseudomonas putida, which naturally accumulate PHAs as intracellular carbon and energy reserves, especially under...
00:46Bioremediation
Bioremediation is the use of prokaryotes, fungi, or plants to remove pollutants from the environment. This process has been used to remove harmful toxins in groundwater as a byproduct of agricultural run-off and also to clean up oil spills.
01:28Microbial Bioremediation of Plastics
Polyethylene terephthalate (PET) is a synthetic polymer widely utilized in the packaging industry, particularly for bottles and containers. Due to its chemical stability and durability, PET accumulates in the environment, contributing significantly to plastic pollution. It comprises repeating units of terephthalic acid and ethylene glycol, resulting in a semi-crystalline structure that is resistant to natural degradation processes.A notable breakthrough in plastic biodegradation came with the...
01:26Microbial Bioremediation of Hydrocarbons
Bioremediation is an environmentally sustainable process that employs living organisms—primarily microorganisms—to degrade or neutralize pollutants from contaminated environments. In oil spills and hydrocarbon pollution, bioremediation involves the use of hydrocarbon-degrading bacteria to transform toxic compounds into less harmful substances. This approach leverages natural microbial metabolic processes and is considered both cost-effective and ecologically favorable compared to physical or...
01:30Microbial Wastewater Treatment
Microbial communities in aquatic ecosystems play a key role in the natural breakdown of contaminants introduced through domestic and industrial effluents. Acting as biological catalysts, these microbes change and mineralize a wide range of organic and inorganic pollutants under different redox conditions.In oxygen-rich surface waters, aerobic heterotrophs lead organic matter breakdown, using oxygen as the terminal electron acceptor to efficiently oxidize substrates to carbon dioxide and water.